Convergence is an oft-used notion in contact linguistics and historical linguistics. Yet it is problematic as an explanatory account for the changes it represents. In this study, we model one specific case of convergence (Duoxu, an endangered Tibeto-Burman language with 9 last speakers) to contribute to a more systematic understanding of the mechanisms underlying this phenomenon. The goals are (1) to address the role of some linguistic and social factors assumed to have an effect on the process of convergence, and (2) to test the following explanations of empirical observations related to phonological convergence: (a) the loss of phonological segments in a language that has undergone convergence is correlated with the relative frequency and markedness of these segments in the combined bilingual repertoire, and (b) widespread bilingualism is a prerequisite for convergence. The results of our agent-based simulation affirm the importance of frequency and markedness of phonological segments in the process of convergence. At the same time, they suggest that the explanation related to widespread bilingualism may not be valid. Our study suggests computer simulations as a promising tool for investigation of complex cases of language change in contact settings.Convergence, agent-based modeling, bilingualism, phonology, markedness, social factors 1 Duoxu, Lizu, and Ersu are currently classified as dialects of the same language, Ersu (e.g. Sun, 1983Sun, , 2001, and, for that reason, share the same ISO 639-3 code (ers). Given that Duoxu, Lizu, and Ersu are not mutually intelligible, we regard them as separate languages rather than dialects of one language (cf. Yu, 2012: 1). 2 The phonological history of Mandarin Chinese, including its important regional variety, SWM, is well documented and understood (e.g. Norman, 1999; Yuan, 2001 and references therein). Notably, SWM is the most homogeneous of all Mandarin groups, whose consonant system, as attested synchronically, has not undergone major change since the 18 th century when Duoxu came in contact with SWM.